The present invention refers to a device for a respirator, which device includes a pipe member arranged to be introduced into the trachea of a patient and which is arranged to supply inhalation gas via the pipe member to the lungs of said patient during a first state and to discharge exhalation gas via the pipe member from the lungs of said patient during a second state.
When a patient is treated by means of a respirator such a pipe member, a so-called endotracheal tube is used, which is a hose that is introduced into the trachea and attached in an airtight manner in the trachea by means of a fixing member, a so-called cuff. Ventilation takes place by supplying air to the lungs during inhalation whereas the exhalation takes place in a passive manner in that the thorax and the diaphragm compress the lungs. The trachea has a natural transport system for transporting secretions upwards. When a conventional endotracheal tube is attached in the trachea, this transport system can not any longer function. The secretions therefore has to be sucked out at regular intervals by means of a catheter which is introduced into the endotracheal tube. Such a catheter suction is combined with a risk of bacterial contamination of the sterile lung region. In connection with the catheter suction or the intermediate accumulation process, movements of accumulations of secretions may generate cough reflexes of the patient. However, resistance from the endotracheal tube does not permit any large or fast air movements, which could contribute to forcing air and thus secretions outwards. During such cough reflexes, the stresses on the fixing member are large. A powerful cough reflex may therefore lead to a spontaneous extubation, i.e. that the endotracheal tube is loosened and makes continued ventilation impossible.
WO-A-00/13730 discloses a device for closed ventilation in which the natural transport system is permitted to function. This known device includes a pipe member, which has a first separate channel for the inhalation gas and a second separate channel for the exhalation gas. In case of a great production of secretions, the second channel could possibly be blocked and thus prevent an efficient gas exchange.
SE-A-0000635-3 discloses a similar device for closed ventilation. This device includes a container for collection of secretions.
GB 2 021 421 discloses a device for a respirator. The device includes a conduit for the supply of inhalation air. The conduit includes a valve arrangement, which permits the exhalation air from a patient to be conveyed out into the environment.
WO93/15782 discloses a device, which is intended to be used during suction of the airways of a patient. During suction a vacuum is applied to the airways. If the pressure in the airways falls below a predetermined value, at which there is a risk of a collapse of the airways, a security valve is open automatically.
U.S. Pat. No. 5,611,336 discloses a device for suction of a patient. The device includes a hose, which is kept in a thin casing and which is intended to be introduced into an endotracheal tube through a protecting member that is applied in front of the mouth of the patient.